A hydrophilic-lipophilic oil-water separation metal mesh and a preparation method thereof

Abstract

The hydrophilic and lipophilic oil-water separation metal mesh is woven by titanium wires, the mesh aperture is 80-300 meshes, the diameter of the titanium wire is 80-300 microns, the surface of the titanium wire has a porous nanometer film with a thickness of 10-30 microns, the porous nanometer film is a porous structure with a pore size of 5-25 microns constructed by titanium nanowires, and the diameter of the titanium nanowire is 40-80 nm. The mechanism of the metal mesh for oil-water separation is that the titanium wire mesh soaked in an alkaline solution at high temperature can quickly form a water film when encountering water, and the oil will float on the surface of the water film. The water film allows water to continue to pass through the mesh holes of the titanium metal mesh, but can block the passage of oil liquids, thereby realizing the rapid separation function of oil and water. The metal mesh can realize rapid and efficient separation of oil and water, is low-carbon and environmentally friendly, the preparation method is simple and easy to operate, the preparation cost is low, and the mass efficient construction and preparation of the oil-water separation metal mesh can be realized.

Description

Technical Field

[0001] This invention relates to the field of oil-water separation technology, specifically to a hydrophilic and oleophilic oil-water separation metal mesh and its preparation method. Background Technology

[0002] The amount of oil-water mixtures produced by the petroleum and metallurgical industries is increasing year by year. Oil-water separation, as an efficient method for treating oil-water mixed waste liquids, has significant industrial applications and environmental protection benefits.

[0003] With the development of technology, the preparation and production of oil-water separation membranes and oil-water separation meshes have been deeply understood, but there are also obvious drawbacks. Existing oil-water separation meshes also have a certain oil-water separation effect, but they mainly use expensive low surface energy materials to modify metal meshes and fabrics, and the process is complex, the preparation requirements are stringent, and they consume a lot of manpower, material resources and financial resources. For example, CN104689602A discloses a method for preparing an inorganic coated oil-water separation mesh. Silica sol is injected into a reactor containing a template under negative pressure, and the template is immersed for 2 hours. The reactor is then sealed and placed in a constant temperature chamber at 60°C for 12 hours. The template is removed to obtain a solid block-shaped micro / nano composite polyhedron. After the obtained block-shaped micro / nano composite polyhedron is dried, it is thoroughly ground into powder and poured into a reactor containing acetone dispersion. A low surface energy silane coupling agent is added for modification. After reacting for 12 hours, a modified micro / nano composite polyhedron suspension is obtained. Through acetone evaporation or re-addition, the percentage of solid mass concentration in the suspension is adjusted to 0.5%–20%. Furthermore, the oil-water separation net disclosed in CN104689602A works by blocking water and allowing oil to pass through, thereby achieving the effect of oil-water separation. However, in reality, the density of oil is less than that of water, and oil will float on the surface of water. Therefore, this oil-water separation net needs to use magnetic stirring to mix the oil and water before it can achieve the separation of oil and water, making it difficult to achieve rapid separation of oil and water. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a hydrophilic and oleophilic oil-water separation metal mesh and its preparation method, which can realize the rapid and efficient separation of oil and water, is low-carbon and environmentally friendly, and its preparation method is simple and easy to implement with low preparation cost, and can realize the large-scale and efficient construction and preparation of oil-water separation metal mesh.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a hydrophilic and oleophilic oil-water separation metal mesh, wherein the metal mesh is a titanium metal mesh woven from titanium metal wires, the mesh size of the titanium metal mesh is 80-300 mesh, the diameter of the titanium metal wires is 80-300 μm, and the surface of the titanium metal wires has a porous nanofilm with a thickness of 10-30 μm, wherein the porous nanofilm is a porous structure with a pore size of 5-25 μm constructed from titanium nanowires, and the diameter of the titanium nanowires is 40-80 nm.

[0006] Preferably, the raw material for the titanium wire is pure titanium or a titanium alloy.

[0007] A method for preparing the above-mentioned oil-water separation metal mesh includes the following steps:

[0008] 1) Prepare untreated titanium wires, remove surface stains from the titanium wires, and weave the titanium wires into a titanium mesh;

[0009] 2) Soak the woven titanium metal mesh in an alkaline solution at high temperature for 1 to 12 hours. The alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution. The temperature of the alkaline solution is 160 to 240°C and the concentration is 0.5 to 2 mol / L.

[0010] 3) After high-temperature soaking, the titanium metal mesh is directly cooled to room temperature in the alkaline solution, and then soaked in the alkaline solution after cooling to room temperature for 1 to 12 hours. After that, the titanium metal mesh is taken out from the alkaline solution, washed with distilled water or deionized water 1 to 3 times, and then air-dried at room temperature to obtain a hydrophilic and oleophilic oil-water separation metal mesh.

[0011] Preferably, the high-temperature soaking time in step 2) is 3 to 6 hours.

[0012] Another method for preparing the above-mentioned oil-water separation metal mesh includes the following steps:

[0013] (1) Prepare untreated titanium wire, remove surface stains from the titanium wire, and soak the titanium wire in an alkaline solution at high temperature for 1 to 12 hours. The alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution. The temperature of the alkaline solution is 160 to 240°C and the concentration is 0.5 to 2 mol / L.

[0014] (2) After high-temperature soaking, the titanium wire is directly cooled to room temperature in the alkaline solution, and then soaked in the alkaline solution after cooling to room temperature for 1 to 12 hours. After that, the titanium wire is taken out from the alkaline solution, washed with distilled water or deionized water 1 to 3 times, and then dried at room temperature. The titanium wire is then woven into a titanium mesh to obtain a hydrophilic and oleophilic oil-water separation metal mesh.

[0015] Preferably, the high-temperature soaking time in step (1) is 3 to 6 hours.

[0016] Compared with existing technologies, this invention has the following advantages: When the hydrophilic and oleophilic oil-water separation metal mesh of this invention is used for oil-water separation, oily liquids cannot pass through, while water can. Its mechanism is as follows: after being soaked in an alkaline solution at high temperature, the titanium metal mesh quickly forms a water film upon contact with water. Oil floats on the surface of this water film. This water film allows water to continue passing through the mesh openings of the titanium metal mesh, but blocks the passage of oily liquids, thus achieving rapid oil-water separation. The oil-water separation metal mesh of this invention has hydrophilic and oleophilic properties, enabling rapid and efficient separation of oil and water, and is low-carbon and environmentally friendly. The preparation method of the oil-water separation metal mesh of this invention is simple and easy to implement; rapid oil-water separation of the metal mesh can be achieved through simple alkaline solution soaking. The preparation cost is low, enabling the large-scale and efficient construction and preparation of oil-water separation metal meshes. Attached Figure Description

[0017] Figure 1 This is a SEM image of the titanium mesh in Example 1 that was not treated with alkaline solution.

[0018] Figure 2 for Figure 1 Enlarged view of a portion of the image;

[0019] Figure 3 This is a contact angle feature diagram of the oil-water separation metal mesh in Example 1;

[0020] Figure 4 SEM image of the titanium metal mesh of the oil-water separation metal mesh in Example 1;

[0021] Figure 5 for Figure 4 Enlarged view of a portion of the image;

[0022] Figure 6 An optical microscope image of the water film formed on the surface of the titanium metal mesh used for oil-water separation in Example 1 when it is used for oil-water separation.

[0023] Figure 7 This is a diagram showing the separation state of the oil-water separation metal mesh in Example 1. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Example 1: A hydrophilic and oleophilic oil-water separation metal mesh, wherein the metal mesh is a titanium metal mesh woven from titanium metal wires, the mesh size of the titanium metal mesh is 200 mesh, the diameter of the titanium metal wires is 100 μm, and the surface of the titanium metal wires has a porous nanofilm with a thickness of 20 μm. The porous nanofilm is a porous structure with a pore size of 10-15 μm constructed from titanium nanowires, and the diameter of the titanium nanowires is 60-70 nm.

[0026] The preparation method of the oil-water separation metal mesh in Example 1 includes the following steps:

[0027] 1) Prepare untreated titanium wires with a diameter of 100μm. Clean the wires three times each with alcohol and deionized water at room temperature to remove surface contaminants. Then, weave the titanium wires into an interlaced titanium mesh using a braiding machine. See the SEM image below. Figure 1 , Figure 1 See the enlarged view corresponding to the dashed box section. Figure 2 This titanium mesh possesses hydrophobic and oleophilic properties, and its contact angle characteristic diagram is shown below. Figure 3 As shown;

[0028] 2) Immerse the woven titanium mesh in a high-temperature and pressure-resistant sealed container filled with an alkaline solution for 6 hours. The alkaline solution is either sodium hydroxide solution or potassium hydroxide solution, and the temperature of the alkaline solution is 230℃ with a concentration of 1mol / L.

[0029] 3) After high-temperature soaking, the titanium mesh was directly cooled to room temperature in the alkaline solution, and then soaked in the alkaline solution after cooling to room temperature for another 6 hours. Afterward, the titanium mesh was removed from the alkaline solution, washed three times with distilled or deionized water, and then air-dried at room temperature to obtain the hydrophilic and oleophilic oil-water separation metal mesh of Example 1. The SEM image of this oil-water separation metal mesh is shown below. Figure 4 , Figure 4 See the enlarged view corresponding to the dashed box section. Figure 5 This oil-water separation metal mesh possesses both superhydrophilic and superoleophilic properties. After its surface is first wetted with water, a water film can quickly form (e.g., ...). Figure 6 As shown in the diagram, oil floats on the surface of the water film. This water film allows water to continue passing through the mesh of the titanium metal mesh, but blocks the passage of oily liquids. This achieves the function of allowing water to pass through while preventing oil from passing through, thus enabling rapid separation of oil and water. The separation state diagram is shown in the diagram below. Figure 7 As shown.

[0030] The hydrophilic and oleophilic oil-water separating metal mesh from Example 1 was cut into circular meshes with a diameter of 20 mm (approximately 3.14 cm²). 2The system was used to separate 20 mL of a mixture of kerosene and water for 10 seconds, 20 mL of a mixture of polyalphaolefin and water for 14 seconds, 20 mL of a mixture of cyclohexane and water for 10 seconds, and 20 mL of a mixture of petroleum ether and water for 12 seconds. The separation rates per square meter were: 6.37 L / s for kerosene and water, 4.55 L / s for polyalphaolefin and water, 6.37 L / s for cyclohexane and water, and 5.31 L / s for petroleum ether and water. The separation efficiencies were: 99.8% for kerosene, 99.3% for polyalphaolefin, 98.8% for cyclohexane, and 98.2% for petroleum ether.

[0031] When the hydrophilic and oleophilic oil-water separation metal mesh from Example 1 was used to separate polyalphaolefins from water, it was found that the separation efficiency of the oil-water separation metal mesh could still be maintained above 98% after being reused 20 times.

[0032] Example 2: A hydrophilic and oleophilic oil-water separation metal mesh, wherein the metal mesh is a titanium metal mesh woven from titanium metal wires, the mesh size of the titanium metal mesh is 200 mesh, the diameter of the titanium metal wires is 100 μm, and the surface of the titanium metal wires has a porous nanofilm with a thickness of 15 μm. The porous nanofilm is a porous structure with a pore size of 15-20 μm constructed from titanium nanowires, and the diameter of the titanium nanowires is 70-80 nm.

[0033] (1) Prepare a titanium wire with a diameter of 100 μm without surface treatment. Clean it three times at room temperature with alcohol and deionized water to remove surface stains. Soak the titanium wire in an alkaline solution at high temperature for 6 hours. The alkaline solution is sodium hydroxide solution or potassium hydroxide solution. The temperature of the alkaline solution is 230℃ and the concentration is 1 mol / L.

[0034] (2) After high-temperature soaking, the titanium wire is directly cooled to room temperature in an alkaline solution, and then soaked in the alkaline solution after cooling to room temperature for 6 hours. After that, the titanium wire is taken out from the alkaline solution, washed 3 times with distilled water or deionized water, and then dried at room temperature. The titanium wire is then woven into an interlaced titanium wire mesh using a weaving machine to obtain the hydrophilic and oleophilic oil-water separation metal mesh of Example 2.

[0035] The hydrophilic and oleophilic oil-water separating metal mesh from Example 2 was cut into circular meshes with a diameter of 20 mm (approximately 3.14 cm²). 2The system was used to separate 20 mL of a mixture of kerosene and water in 11 seconds, 20 mL of a mixture of polyalphaolefin and water in 16 seconds, 20 mL of a mixture of cyclohexane and water in 12 seconds, and 20 mL of a mixture of petroleum ether and water in 13 seconds. The separation rates per square meter were: kerosene and water 5.79 L / s, polyalphaolefin and water 3.98 L / s, cyclohexane and water 5.31 L / s, and petroleum ether and water 4.90 L / s, respectively. The separation efficiencies were: kerosene 98.6%, polyalphaolefin 97.9%, cyclohexane 96.5%, and petroleum ether 95.9%, respectively.

[0036] When the hydrophilic and oleophilic oil-water separation metal mesh from Example 2 was used to separate polyalphaolefins from water, it was found that the separation efficiency of the oil-water separation metal mesh could still be maintained above 96% after being reused 20 times.

Claims

1. A hydrophilic and oleophilic oil-water separation metal mesh, characterized in that, The metal mesh is a titanium metal mesh woven from titanium metal wires. The mesh size of the titanium metal mesh is 80-300 mesh, the diameter of the titanium metal wires is 80-300 μm, and the surface of the titanium metal wires has a porous nanofilm with a thickness of 10-30 μm. The porous nanofilm is a porous structure with a pore size of 5-25 μm constructed from titanium nanowires, and the diameter of the titanium nanowires is 40-80 nm. The method for preparing the oil-water separation metal mesh includes the following steps: 1) Prepare untreated titanium wires, remove surface stains from the titanium wires, and weave the titanium wires into a titanium mesh; 2) Soak the woven titanium metal mesh in an alkaline solution at high temperature for 1 to 12 hours. The alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution. The temperature of the alkaline solution is 160 to 240°C and the concentration is 0.5 to 2 mol / L. 3) After high-temperature soaking, the titanium metal mesh is directly cooled to room temperature in the alkaline solution, and then soaked in the alkaline solution after cooling to room temperature for 1 to 12 hours. After that, the titanium metal mesh is taken out from the alkaline solution, washed with distilled water or deionized water 1 to 3 times, and then air-dried at room temperature to obtain a hydrophilic and oleophilic oil-water separation metal mesh. Alternatively, the method for preparing the oil-water separation metal mesh includes the following steps: (1) Prepare untreated titanium wire, remove surface stains from the titanium wire, and soak the titanium wire in an alkaline solution at high temperature for 1 to 12 hours. The alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution. The temperature of the alkaline solution is 160 to 240°C and the concentration is 0.5 to 2 mol / L. (2) After high-temperature soaking, the titanium wire is directly cooled to room temperature in the alkaline solution, and then soaked in the alkaline solution after cooling to room temperature for 1 to 12 hours. After that, the titanium wire is taken out from the alkaline solution, washed with distilled water or deionized water 1 to 3 times, and then dried at room temperature. The titanium wire is then woven into a titanium mesh to obtain a hydrophilic and oleophilic oil-water separation metal mesh.

2. The oil-water separation metal mesh according to claim 1, characterized in that, The raw material for the titanium wire is pure titanium or a titanium alloy.

3. The method for preparing the oil-water separation metal mesh according to claim 1, characterized in that, The high-temperature soaking time is 3 to 6 hours.

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